title: Leptin cut-off values for determination of metabolic syndrome: third national surveillance of risk factors of non-communicable diseases in Iran (SuRFNCD-2007).
abstract: Leptin is strongly contributed to the clustering of metabolic syndrome (MetS) components and potentially can be regarded as a single predictor of MetS. This population-based study, for the first time, reports the diagnostic accuracy of different leptin cut-points for determining MetS. Further, the current study compares the predictive ability of the appropriate threshold of leptin with insulin resistance. Data of the individuals without history of known diabetes mellitus, aged 25-64 years, from the third national surveillance of risk factors of non-communicable diseases (SuRFNCD-2007) were analyzed. MetS was defined due to either adult treatment panel III (ATPIII) or the modified international diabetes federation (IDF) criteria. Receiver-operating characteristic (ROC) curves were depicted to define cut-off of serum leptin, using the maximum Youden index and the shortest distance methods. Further, the values of leptin cut-offs in prediction of MetS were compared with those of insulin resistance (defined as homeostasis model assessment of insulin resistance >1.775). In men, the optimal cut-offs of leptin for IDF- and ATPIII-defined MetS were 3.6 ng/ml (positive predictive value, PPV: 56.5%; negative predictive value, NPV: 72.7%) and 4.1 ng/ml (PPV: 49.6%; NPV: 78.1%), respectively. In women, the optimal threshold was equal to 11.0 ng/ml (PPV: 53.8%; NPV: 73.0% for IDF criteria and PPV: 60.1%; NPV: 64.9% for ATPIII criteria). The diagnostic accuracy of these values in identifying MetS was similar to that of insulin resistance. Therefore, leptin is comparable to insulin resistance in identifying MetS and can be used as single predictor of MetS.
authors.affiliation: Endocrinology and Metabolism Research Center (EMRC), Vali-Asr Hospital, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran. esteghamati@tums.ac.ir
authors.forename: Alireza
authors.initials: A
authors.lastname: Esteghamati
authors.forename: Ali
authors.initials: A
authors.lastname: Zandieh
authors.forename: Basira
authors.initials: B
authors.lastname: Zandieh
authors.forename: Omid
authors.initials: O
authors.lastname: Khalilzadeh
authors.forename: Alipasha
authors.initials: A
authors.lastname: Meysamie
authors.forename: Manouchehr
authors.initials: M
authors.lastname: Nakhjavani
authors.forename: Mohammad Mehdi
authors.initials: MM
authors.lastname: Gouya
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D007492:Iran / Q000453:epidemiology; D020738:Leptin / Q000097:blood*; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology* / Q000208:ethnology* / Q000503:physiopathology; D008875:Middle Aged; D011159:Population Surveillance; D011237:Predictive Value of Tests; D012372:ROC Curve; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D020738:Leptin